//--------------------------------------------------------------------------
//	Copyright (c) 1998-2004, Drew Davidson and Luke Blanshard
//  All rights reserved.
//
//	Redistribution and use in source and binary forms, with or without
//  modification, are permitted provided that the following conditions are
//  met:
//
//	Redistributions of source code must retain the above copyright notice,
//  this list of conditions and the following disclaimer.
//	Redistributions in binary form must reproduce the above copyright
//  notice, this list of conditions and the following disclaimer in the
//  documentation and/or other materials provided with the distribution.
//	Neither the name of the Drew Davidson nor the names of its contributors
//  may be used to endorse or promote products derived from this software
//  without specific prior written permission.
//
//	THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
//  "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
//  LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
//  FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
//  COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
//  INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
//  BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
//  OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
//  AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
//  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF
//  THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
//  DAMAGE.
//--------------------------------------------------------------------------
package org.more.ognl;
import java.util.ArrayList;
import java.util.Collection;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;
/**
* A Map that uses ints as the keys.
* <p>Use just like any java.util.Map, except that the keys must be ints.
* This is much faster than creating a new Integer for each access.</p>
* <p>For non-Map access (faster) use the put(int, Object) method.</p>
* <p>This class implements Map for convenience, but this is not the most
* efficient usage.</p>
* @see java.util.HashMap
* @see java.util.Map
*/
@SuppressWarnings({ "rawtypes", "unchecked" })
public class IntHashMap extends Object implements Map {
    private Entry table[];
    private int   count;
    private int   threshold;
    private float loadFactor;
    /*===================================================================
        Private static classes
      ===================================================================*/
    private static class IntHashMapIterator implements Iterator {
        boolean keys;
        int     index;
        Entry   table[];
        Entry   entry;
        IntHashMapIterator(Entry table[], boolean keys) {
            super();
            this.table = table;
            this.keys = keys;
            this.index = table.length;
        }
        /*===================================================================
            Iterator interface
          ===================================================================*/
        public boolean hasNext() {
            if (entry != null)
                return true;
            while (index-- > 0)
                if ((entry = table[index]) != null)
                    return true;
            return false;
        }
        public Object next() {
            if (entry == null)
                while ((index-- > 0) && ((entry = table[index]) == null)) {
                    /* do nothing */
                }
            if (entry != null) {
                Entry e = entry;
                entry = e.next;
                return keys ? new Integer(e.key) : e.value;
            }
            throw new NoSuchElementException("IntHashMapIterator");
        }
        public void remove() {
            throw new UnsupportedOperationException("remove");
        }
    }
    /*===================================================================
        Public static classes
      ===================================================================*/
    public static class Entry extends Object {
        int    hash;
        int    key;
        Object value;
        Entry  next;
        public Entry() {
            super();
        }
    }
    /*===================================================================
        Constructors
      ===================================================================*/
    public IntHashMap(int initialCapacity, float loadFactor) {
        super();
        if (initialCapacity <= 0 || loadFactor <= 0.0)
            throw new IllegalArgumentException();
        this.loadFactor = loadFactor;
        table = new Entry[initialCapacity];
        threshold = (int) (initialCapacity * loadFactor);
    }
    public IntHashMap(int initialCapacity) {
        this(initialCapacity, 0.75f);
    }
    public IntHashMap() {
        this(101, 0.75f);
    }
    /*===================================================================
        Protected methods
      ===================================================================*/
    protected void rehash() {
        int oldCapacity = table.length;
        Entry oldTable[] = table;
        int newCapacity = oldCapacity * 2 + 1;
        Entry newTable[] = new Entry[newCapacity];
        threshold = (int) (newCapacity * loadFactor);
        table = newTable;
        for (int i = oldCapacity; i-- > 0;)
            for (Entry old = oldTable[i]; old != null;) {
                Entry e = old;
                int index = (e.hash & 0x7FFFFFFF) % newCapacity;
                old = old.next;
                e.next = newTable[index];
                newTable[index] = e;
            }
    }
    /*===================================================================
        Public methods
      ===================================================================*/
    public final boolean containsKey(int key) {
        int index = (key & 0x7FFFFFFF) % table.length;
        for (Entry e = table[index]; e != null; e = e.next)
            if ((e.hash == key) && (e.key == key))
                return true;
        return false;
    }
    public final Object get(int key) {
        int index = (key & 0x7FFFFFFF) % table.length;
        for (Entry e = table[index]; e != null; e = e.next)
            if ((e.hash == key) && (e.key == key))
                return e.value;
        return null;
    }
    public final Object put(int key, Object value) {
        int index = (key & 0x7FFFFFFF) % table.length;
        if (value == null)
            throw new IllegalArgumentException();
        for (Entry e = table[index]; e != null; e = e.next)
            if ((e.hash == key) && (e.key == key)) {
                Object old = e.value;
                e.value = value;
                return old;
            }
        if (count >= threshold) {
            // Rehash the table if the threshold is exceeded.
            rehash();
            return put(key, value);
        }
        Entry e = new Entry();
        e.hash = key;
        e.key = key;
        e.value = value;
        e.next = table[index];
        table[index] = e;
        ++count;
        return null;
    }
    public final Object remove(int key) {
        int index = (key & 0x7FFFFFFF) % table.length;
        for (Entry e = table[index], prev = null; e != null; prev = e, e = e.next)
            if ((e.hash == key) && (e.key == key)) {
                if (prev != null)
                    prev.next = e.next;
                else
                    table[index] = e.next;
                --count;
                return e.value;
            }
        return null;
    }
    /*===================================================================
        Map interface
      ===================================================================*/
    public int size() {
        return count;
    }
    public boolean isEmpty() {
        return count == 0;
    }
    public Object get(Object key) {
        if (!(key instanceof Number))
            throw new IllegalArgumentException("key is not an Number subclass");
        return get(((Number) key).intValue());
    }
    public Object put(Object key, Object value) {
        if (!(key instanceof Number))
            throw new IllegalArgumentException("key cannot be null");
        return put(((Number) key).intValue(), value);
    }
    public void putAll(Map otherMap) {
        for (Iterator it = otherMap.keySet().iterator(); it.hasNext();) {
            Object k = it.next();
            put(k, otherMap.get(k));
        }
    }
    public Object remove(Object key) {
        if (!(key instanceof Number))
            throw new IllegalArgumentException("key cannot be null");
        return remove(((Number) key).intValue());
    }
    public void clear() {
        Entry tab[] = table;
        for (int index = tab.length; --index >= 0;)
            tab[index] = null;
        count = 0;
    }
    public boolean containsKey(Object key) {
        if (!(key instanceof Number))
            throw new InternalError("key is not an Number subclass");
        return containsKey(((Number) key).intValue());
    }
    public boolean containsValue(Object value) {
        Entry tab[] = table;
        if (value == null)
            throw new IllegalArgumentException();
        for (int i = tab.length; i-- > 0;)
            for (Entry e = tab[i]; e != null; e = e.next)
                if (e.value.equals(value))
                    return true;
        return false;
    }
    public Set keySet() {
        Set result = new HashSet();
        for (Iterator it = new IntHashMapIterator(table, true); it.hasNext();)
            result.add(it.next());
        return result;
    }
    public Collection values() {
        List result = new ArrayList();
        for (Iterator it = new IntHashMapIterator(table, false); it.hasNext();)
            result.add(it.next());
        return result;
    }
    public Set entrySet() {
        throw new UnsupportedOperationException("entrySet");
    }
}